[gtk/wip/smcv/reliable-gresource] build: Add an option to use more conservative GResource embedding

[Simon McVittie <smcv src gnome org>]

commit 43e4552ec28ea4d01f82b93992bb519a97a77267
Author: Simon McVittie <smcv debian org>
Date:   Mon Aug 15 22:24:26 2022 +0100

    build: Add an option to use more conservative GResource embedding
    
    Doing clever things with objcopy is faster, but also doesn't work on
    all toolchains and architectures: in particular, Debian has had trouble
    with this on arm and mips.
    
    Developers will want to leave this option switched on for faster
    incremental builds (unless their toolchain doesn't support it), but in
    a distro build environment where we are compiling all of GTK every time,
    the cost of potentially unreliable builds is higher than the cost of
    using slower but more conservative GResource embedding.
    
    Resolves: https://gitlab.gnome.org/GNOME/gtk/-/issues/5107
    Signed-off-by: Simon McVittie <smcv debian org>

 gtk/meson.build   | 15 ++++++++++++++-
 meson_options.txt |  5 +++++
 2 files changed, 19 insertions(+), 1 deletion(-)
---
diff --git a/gtk/meson.build b/gtk/meson.build
index 2e404f2ac4..46f886f7af 100644
--- a/gtk/meson.build
+++ b/gtk/meson.build
@@ -866,15 +866,28 @@ if not fs.exists('theme/Default/Default-light.css')
 endif
 
 
+fast_gresource_embedding = get_option('fast_gresource_embedding')
+
 objcopy_supports_add_symbol = false
 objcopy = find_program('objcopy', required : false)
 if objcopy.found()
   objcopy_supports_add_symbol = run_command(objcopy, '--help').stdout().contains('--add-symbol')
 endif
+fast_gresource_embedding = fast_gresource_embedding and objcopy_supports_add_symbol
 
 ld = find_program('ld', required : false)
+fast_gresource_embedding = fast_gresource_embedding and ld.found()
+
+if meson.is_cross_build() or build_machine.system() != 'linux'
+  fast_gresource_embedding = false
+endif
+
+if build_machine.cpu_family() in ['arm', 'mips']
+  # Known not to work reliably on these architectures
+  fast_gresource_embedding = false
+endif
 
-if not meson.is_cross_build() and build_machine.cpu_family() != 'arm' and build_machine.system() == 'linux' 
and objcopy.found() and objcopy_supports_add_symbol and ld.found()
+if fast_gresource_embedding
   glib_compile_resources = find_program('glib-compile-resources')
 
   # Create the resource blob
diff --git a/meson_options.txt b/meson_options.txt
index 2084ab86e1..078e76f520 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -78,6 +78,11 @@ option('f16c',
        value: 'enabled',
        description: 'Enable F16C fast paths (requires F16C)')
 
+option('fast_gresource_embedding',
+       type: 'boolean',
+       value: true,
+       description: 'Speed up GResource compilation (does not work on all architectures)')
+
 # Documentation and introspection
 
 option('gtk_doc',